JP3273477B2 - Light air secondary battery - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a secondary battery capable of both charging and discharging, and more particularly to a light air secondary battery which is discharged by an oxidation reaction and charged by light energy.

[0002]

2. Description of the Related Art Attempts to charge a secondary battery with light energy such as solar visible light have been made before. Such batteries include amorphous silicon solar batteries and nickel-cadmium storage batteries and lead storage batteries. 2. Description of the Related Art A solar storage battery in which a secondary battery is combined is known.

[0003] This solar battery will be described with reference to FIG. FIG. 5 shows an equivalent circuit diagram of the solar battery. The solar battery includes a solar cell 1, a battery 2 for storing power obtained by the solar cell 1, and a battery 2 for storing a voltage generated in the solar cell 1. Voltage adjustment circuit 3 that adjusts to a voltage suitable for charging
And a backflow prevention diode 4 for preventing a current flowing from the solar cell 1 to the storage battery 2 from flowing back. This solar battery is a two-stage (indirect) optical secondary battery in which the solar battery 1 generates power and the power obtained by the solar battery 1 is stored in the storage battery 2.

[0004]

However, in the conventional photorechargeable battery, since the components such as the voltage adjusting circuit 3 and the backflow prevention diode 4 are essential, the structure of the photorechargeable battery is complicated. It has the disadvantage of being large.

In addition, in order for the conventional light secondary battery to function properly, it is necessary to adjust the power generated by the solar cell 1 to a voltage suitable for charging the storage battery 2, and the power consumed for this adjustment is required. There is a problem that the energy loss is large. In addition, since the above-mentioned photorechargeable battery undergoes three energy conversion steps of light → electricity → electrochemistry, the number of components for this energy conversion step is increased, or energy loss due to this energy conversion step is caused. There is also a problem such as an increase in Further, manufacturing the solar cell 1 also has difficulty in manufacturing the solar cell 1 such that a relatively advanced manufacturing technique such as pn junction manufacturing is required.

FIG. 6 shows a configuration diagram of a conventional photochemical secondary battery. Reference numeral 5 in the figure denotes a battery container, 5a
Is a lid for sealing the battery container, 6 is a separator, 7 is a photoelectrode made of an n-type semiconductor part, 8a is a charging electrode, 8
b is a discharge electrode, and 9 is an electrolyte.

[0007] These photochemical secondary batteries make use of the electrochemical characteristics of the semiconductor-electrolyte interface, that is, the photoenergy is converted by utilizing the bending of the energy band generated when the semiconductor electrode is brought into contact with the electrolyte. The generated electrons are taken out of the semiconductor electrode, and the electric energy of the electrons is electrochemically stored in the charging electrode. The light conversion part of the photochemical secondary battery shown in FIG. 6 is configured by merely immersing the semiconductor electrode 7 in the electrolyte 9,
It is superior to the conventional light-air secondary battery shown in FIG. 5 which requires an amorphous silicon solar cell or the like in that a relatively advanced manufacturing technique such as a pn junction manufacturing technique is not required. However, the photochemical secondary battery requires one or two electrodes for performing light charging in addition to the positive electrode and the negative electrode in a normal secondary battery, and has a disadvantage that the structure of the battery is complicated.

On the other hand, if a metal negative electrode member and an n-type semiconductor are integrally formed and electrons generated by light energy on the n-type semiconductor are used to reduce the negative electrode member without being taken out of the electrode. In addition, the electrode configuration can be composed of a negative electrode in which an n-type semiconductor and a negative electrode member made of metal are formed in combination, and a positive electrode, and the battery structure can be simplified. However, usually, at the contact interface between metal and semiconductor,
In many cases, a barrier is formed in the energy band, which is a path of electrons, and simply contacting a metal with an n-type semiconductor efficiently converts electrons generated by light energy on the semiconductor to a metal negative electrode member. There was a disadvantage that it could not be transmitted.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and is excellent in energy saving by charging with light energy and not requiring a charger. By forming a negative electrode in a composite with a semiconductor and a metal, the negative electrode and the positive electrode are formed. It is an object of the present invention to provide a light-air secondary battery in which a simple battery configuration including two electrodes can be obtained, and in which the transfer of electrons from a semiconductor to a metal is improved.

[0010]

A light air 2 according to claim 1.
The secondary battery has a positive electrode having an oxygen catalyst, a negative electrode, an electrolyte in contact with the positive electrode and the negative electrode, and a battery case in which the positive electrode, the negative electrode, and the electrolyte are accommodated. A negative electrode member, a metal layer electrically connected to the negative electrode member, for reducing a barrier in an energy band at a metal-semiconductor interface, and an n-type semiconductor portion electrically connected to the metal layer. The metal layer is integrally adhered between the negative electrode member and the n-type semiconductor portion, and the battery case is provided with a light receiving portion for inputting light to the n-type semiconductor portion of the negative electrode. It is a feature.

According to a second aspect of the present invention, the negative electrode member is discharged by an oxidation reaction of the negative electrode member and a reduction reaction of oxygen, and oxidized by the discharge by applying light energy to the n-type semiconductor portion. Is reduced and charged.

[0012]

In the photo-air secondary battery of the present invention, the discharge is caused by the oxidation reaction of the metal negative electrode member, and the bending of the energy band formed by immersing the n-type semiconductor portion in the electrolyte is utilized. Then, light energy is converted into electrochemical energy, and charged by the light energy. Since the metal layer for reducing the barrier on the energy band between the metal and the semiconductor is integrally bonded between the metal negative electrode member and the n-type semiconductor portion and electrically connected to these, respectively. The function of the negative electrode and the photoelectrode in the conventional photochemical secondary battery can be combined into one electrode. On the other hand, during charging, electric power is generated by applying light energy to the n-type semiconductor portion, and this power is transmitted from the n-type semiconductor portion to the negative electrode member without being blocked by the semiconductor-metal interface. The efficiency of light energy used for reduction is improved. Then, at the time of discharging, a product generated by the reduction at the time of charging is oxidized by oxygen in the air, thereby discharging.

[0013] Further, since the metal layer is integrally bonded between the metal negative electrode member and the n-type semiconductor portion, the metal layer is brought into contact with the surface of the n-type semiconductor portion so that current can be efficiently supplied from the n-type semiconductor portion. The function of the current collector is also performed by the negative electrode member, so that the current collector and the like become unnecessary. Therefore, a simple two-pole configuration including only the positive electrode and the negative electrode can be achieved without lowering the energy efficiency during charging.

[0014]

FIG. 1 shows a first embodiment of a light-air secondary battery according to the present invention.
It is sectional drawing of the Example of FIG. In the figure, reference numeral 10 denotes a positive electrode made of a porous oxygen catalyst, 11 denotes a negative electrode, 12 denotes a positive electrode 10 and a negative electrode 1.
1, an electrolyte in contact with 1, 13 a separator, 14 a positive electrode terminal electrically connected to the positive electrode 10, 15 a negative electrode terminal electrically connected to the negative electrode 11, 16 a battery case, 17
Is a water-repellent film. FIG. 2 is an external perspective view of such a light-air secondary battery according to the first embodiment.

The positive electrode 10 and the negative electrode 11 are both formed in a square shape, for example, one side is 1 cm and the other side is 3 cm. Here, the shape of the positive electrode 10 and the negative electrode 11 is not limited to a rectangular shape, but may be a polygonal shape other than a square, a disk shape, or a cylindrical shape in consideration of the shape and size of the battery case 16. May be formed. The positive electrode 10 is formed to have a structure in which platinum fine particles are supported as an oxygen catalyst on a porous carbon plate having a thickness of 1 mm.

The negative electrode 11 is connected to a negative electrode terminal 15 and has a 1 mm thick negative electrode member 11a made of cobalt, and a metal layer 11b integrally disposed on the surface of the negative electrode member 11 for reducing a barrier at a semiconductor-metal interface. And an n-type semiconductor portion 11c integrally provided on the surface of the metal layer 11b and converting light energy into electric energy. The negative electrode member 11a and the n-type semiconductor portion 11c are integrally attached to both surfaces of the metal layer 11b, respectively.
b are electrically connected to each other. The negative electrode member 11 a is disposed at a position facing the positive electrode 10.
The metal layer 11b is composed of an alloy layer having a thickness of 0.3 μm. This alloy has a weight ratio of 84% of gold and 12% of germanium.
% And nickel 4%. n-type semiconductor unit 1
1c is disposed at a position facing the light receiving portion 16a of the battery case 16 described later, and is formed of an n-type gallium phosphide single crystal semiconductor having a thickness of 0.2 mm. Here, these negative electrode member 11a, metal layer 11b, n-type semiconductor portion 11c
Is formed in an appropriate thickness and shape in consideration of the shape and size of the battery case 16, the required battery capacity, and the like.

The electrolyte 12 is an aqueous solution of potassium hydroxide having a concentration of 1 mol / l, and is filled in a battery case 16 described later. The separator 13 is made of glass fiber, is disposed between the positive electrode 10 and the negative electrode 11, and has a structure through which the electrolyte 12 can pass.

The battery case 16 has a rectangular parallelepiped shape made of acrylic resin, and has a light receiving portion 16a made of a light transmitting material such as a transparent acrylic plate also serving as a front surface, and a plate-shaped air transmitting portion 16b provided on the back surface. A large number of air holes 16c are formed in the air permeable portion 16b. The battery case 16 includes a positive electrode 10 disposed on the air permeable portion 16b side, a negative electrode 11 disposed on the light receiving portion 16a side, a space between the positive electrode 10 and the negative electrode 11, and a light receiving portion 16a and the negative electrode 11 , The liquid electrolyte 12 filled between the positive electrode 10 and the negative electrode 1
1 and a separator 13 through which the electrolyte 12 can pass. The size of the battery case 16 is, for example, 3.5 cm in width, 1.6 cm in depth, and 0.7 cm in height.

The water-repellent film 17 is disposed between the air permeable portion 16b of the battery case 16 and the positive electrode 10, is made of porous tetrafluoroethylene resin, has air permeability, and has The electrolyte 12 is prevented from flowing out of the battery due to the water repellency of the battery.

In the light-air secondary battery of this embodiment, the hydrophilic positive electrode 10 and the water-repellent film 17 are brought into contact with each other to form a three-phase gas-liquid-solid phase comprising oxygen, the electrolyte 12 and the positive electrode 10. The area of the interface is increased, and the discharge reaction based on the reduction of oxygen in the air is efficiently performed. Therefore, the positive electrode 10 is made of a porous oxygen catalyst in order to smoothly perform a discharge reaction of oxygen in the air for the purpose of increasing the three-phase interface field.
However, when configuring a battery used for low-rate (low-current) discharge, it is not necessarily required to be porous, and a plate-shaped positive electrode 10 may be used.

The operation at the time of charging and discharging of the photo-air secondary battery in the above embodiment will be briefly described below. When discharging,
On the negative electrode 11, a metal negative electrode member 11a forming the negative electrode 11
Reacts with hydroxyl ions and water molecules in the electrolyte 12 to finally generate a metal oxide and supply electrons to an external load through the negative electrode terminal 15. On the other hand, on the positive electrode 10, at a three-phase interface formed by the oxygen taken in from the air, the electrolyte 12, and the oxygen catalyst (positive electrode) 10, the oxygen, water in the electrolyte 12, and the negative electrode are supplied (discharged) through a load. Reacts with the electrons to form hydroxyl ions. In this discharge reaction, the positive electrode 10
And the reaction in the negative electrode member 11a are canceled out, so that the electrolyte 1
No reduction of 2 occurs. In addition, oxygen, which is a positive electrode active material, is taken in from the air via the air permeable portion 16b of the battery case 16, so that its consumption does not matter. After all,
The part changed by this discharge reaction is the negative electrode member 11a, and a metal oxide is generated by the discharge reaction. Therefore, charging the photo-air secondary battery of this embodiment is nothing but reducing the metal oxide.

At the time of charging, the n-type semiconductor portion 11c of the negative electrode 11
N-type semiconductor part 1 whose energy band is bent upward toward electrolyte 12 at the contact interface between
Irradiate the surface of 1c with light energy such as the sun or fluorescent light,
Electrons are excited in the conduction band of the n-type semiconductor portion 11c to generate holes in the valence band. The holes are carried toward the electrolyte 12 along the bending of the band, and react with hydroxyl ions on the surface of the negative electrode member 11a to generate oxygen and water. On the other hand, the electrons excited in the conduction band move to the negative electrode member 11a of the negative electrode 11 along the bending of the band, and eventually reach the surface of the negative electrode member 11a in contact with the electrolyte 12. Here, the electrons react with water in the electrolyte 12 to generate hydroxyl ions, and reduce metal oxides, which are discharge products of the negative electrode member 11a. Through the above process, the photocharge reaction proceeds.

Here, the negative electrode member 11a and the n-type semiconductor portion 1
1c increases the donor concentration on the surface of the semiconductor. As a result, the width of the energy band barrier at the metal-semiconductor interface becomes very thin, and electrons generated by light energy are efficiently transmitted to the metal negative electrode member 11a without being affected by the barrier.

The change in voltage between the positive terminal 14 and the negative terminal 15 during charging and discharging in the photo-air secondary battery shown in this embodiment is shown by a solid line in FIG. A xenon lamp was used as a light source for light charging, and the intensity of irradiated light was 50 mW. During discharging, a constant current discharge of 1 mA was performed.

(Comparative Example) A photo-air secondary battery was manufactured in the same manner as in the first example except that an electrode having a structure in which cobalt was directly contacted with gallium phosphide was used as a negative electrode. The change in voltage between the positive terminal and the negative terminal during charging and discharging of this battery is shown by a broken line in FIG. As shown by the broken line in FIG.
It can be seen that the voltage rise during light charging is small and the electric capacity during discharging is small.

As the material of the positive electrode 10, in addition to the platinum-carrying carbon plate, carbon or nickel,
Materials supporting t or Pd (Pd-C, Pt-Ni, Pd
-Ni), and Pt, Pd, Ir, Rh, Os, R
u, Pt-Co, Pt-Au, Pt-Sn, Pd-A
u, Ru-Ta, Pt-Pd-Au, Pt-oxide, A
u, Ag, Ag-C, Ni-P, Ag-Ni-P, Raney nickel, Ni-Mn, Ni-cobalt oxide, Cu-
Noble metals and alloys such as Ag, Cu-Au and Raney silver, nickel boride, cobalt boride, tungsten carbide, titanium hydroxide, tungsten phosphide, niobium phosphide, carbides of transition metals, spinel compounds, silver oxide, tungsten oxide , Inorganic compounds such as perovskite-type ionic crystals of transition metals, and phthalocyanines, metal phthalocyanines,
It is preferable to be composed of any of organic compounds such as activated carbon and quinones.

The material of the negative electrode member 11a forming the negative electrode 11 is Ti, Zn, Fe, Pb, Al, Co, H
f, V, Nb, Ni, Pd, Pt, Cu, Ag, Cd,
In, Ge, Sn, Bi, Th, Ta, Cr, Mo,
A metal such as W, Pr, U, or at least a part of the metal is composed of an oxide of the metal, and a composite component metal or alloy thereof.

As the material of the n-type semiconductor portion 11c of the negative electrode 11, in addition to gallium phosphide (Gap), GaAs, Al
As, ZnS, AlSb, InP, CdS, GaSb,
Compound semiconductors such as InAs, inorganic semiconductors such as Si, Ge and Se, condensed polycyclic aromatic compounds such as anthracene, pyrene, phthalocyanine and copper phthalocyanine; and polymers such as polyacetylene, polyaniline, polyparaphenylene and polypyrrole. Preferably.

The combination of the negative electrode member 11a of the negative electrode 11 and the n-type semiconductor portion 11c is such that the potential level at the lower end of the conduction band of the n-type semiconductor portion 11c at the contact interface between the n-type semiconductor portion 11c and the electrolyte 12 is negative. Any combination may be used as long as the combination constitutes a potential lower than the oxidation-reduction potential of the substance, and the type of the member is not particularly limited.

The metal layer 11b contains 84% by weight of gold,
Setting germanium to 12% and nickel to 4% is desirable in that the effect of reducing the barrier at the metal-semiconductor interface is high, but the barrier reducing effect can be obtained with other composition ratios. As a material of the metal layer 11b, besides gold-germanium-nickel, metals such as Au and In, Au-Ge, Au-Si, Au-Zn, and Au-
Ge-Pt, Au-Ge-In, Au-Pt-Ti, A
g-Ge-Ni, Ag-Ge-Pt, Ag-Ge-In
Are desirable.

As the electrolyte 12, in addition to potassium hydroxide, a base such as sodium hydroxide and ammonium chloride, and a liquid electrolyte such as other weak acids are used. Also,
Although the charging performance is deteriorated, a solution of a strong acid such as sulfuric acid or hydrochloric acid or a salt solution of these strong acids can be used. In the present embodiment, the liquid electrolyte 12 is used as described above. However, the electrolyte 12 is not limited to the liquid, and the electron transfer between the positive electrode 10 and the negative electrode 11 through the electrolyte 12 is hindered. As long as the electrolyte cannot be used, any form of electrolyte such as a solid or paste can be used.

Although the separator 13 is made of glass fiber in this embodiment, the separator 12 is made of a non-woven fabric of polyamide fiber, a non-woven fabric of polyolefin fiber, cellulose, synthetic resin or the like.
The material is not particularly limited as long as it has durability against.

The battery case 16 is not particularly limited as long as it is made of a material such as ABS resin and fluororesin which is not affected by the electrolyte 12. However, the light receiving portion 16a located on the negative electrode 11 side of the battery case 16 is a member (colorless or colored) that transmits at least a part of visible light and a part of ultraviolet light, for example, glass, quartz glass, acrylic, It is composed of a transparent plate or film made of styrene or the like. Of course, the entire battery case 16 may be made of such a member as a transparent plate or a transparent film. In the present embodiment, the battery case 16 is formed in a box shape, but may be formed in a polyhedral shape, a disk shape, a cylindrical shape, or the like.

The light transmitting portion 16a is configured to transmit light because the negative electrode 11
When the irradiation light reaches the surface of the n-type semiconductor portion 11c, the irradiation light is absorbed or reflected by the battery case 16, and the light energy reaching the surface of the n-type semiconductor portion 11c is extremely reduced. This is to prevent it.

The material of the water-repellent film 17 is preferably made of a fluorine-based resin such as porous tetrafluoroethylene or a silicon-based resin. In the present embodiment, the film-shaped water-repellent film 17 is used.
The b-side is subjected to a water-repellent treatment using a fluororesin or the like, so that the water-repellent film 17
The water-repellent positive electrode 11 is directly connected to the battery case 1 without using
6 can be configured to be in close contact with the air permeable portion 16b.

<Second Embodiment> FIG. 4 is a sectional view showing the structure of a second embodiment of the present invention. This second embodiment is:
The bottom portion 16b 'of the battery case 16 on the side of the positive electrode 10 is formed of an oxygen-permeable member. Other configurations of the second embodiment are the same as those of the first embodiment. The battery case 16
The bottom portion 16b 'on the side of the positive electrode 10 was formed of an oxygen-permeable member because oxygen outside the battery was converted to a positive electrode 10 containing an oxygen catalyst.
This is similar to the purpose of the first embodiment in which a large number of air holes are formed in the air permeable portion 16b of the battery case 16 in order to diffuse and move to the surface.

The oxygen permeable member is made of ethyl cellulose,
It is preferable to be made of a material such as celluloses, acetates, and butyrates, but the material is not limited to these as long as the member has oxygen permeability.

As described above, by employing the configuration shown in the above embodiment, it is possible to perform discharge using oxygen in the air as an energy source and charge using light energy, which are not available in the conventional photo-air secondary battery. In addition, it is possible to provide a light air secondary battery which is excellent in energy saving and does not require a charger and has a high energy density.

Since the n-type semiconductor portion 11c is provided separately from the negative electrode member 11a, an n-type semiconductor portion 11c that is optimal for the material of the negative electrode member 11a can be used as an active material, and the light conversion efficiency can be improved. A light-air secondary battery can be obtained. Further, since the negative electrode member 11a and the n-type semiconductor portion 11c are integrally formed via the metal layer 11b,
The structure of the photo-air secondary battery can be simplified as compared with the case where the n-type semiconductor portion 11c is arranged at intervals on the negative electrode member 11a.

Particularly, between the negative electrode member 11a made of metal and the n-type semiconductor portion 11c, a metal layer 11b for reducing the barrier in the energy band at the metal-semiconductor interface is provided between the negative electrode member 11a and the n-type semiconductor portion 11c. Are bonded together in a state of being electrically connected to the n-type semiconductor unit 1.
The electric energy generated by the light energy in 1c can be efficiently transmitted to the negative electrode member 11a.

[0041]

As described above, the light air 2 of the present invention is used.
According to the following battery, a positive electrode having an oxygen catalyst, a negative electrode, an electrolyte in contact with the positive electrode and the negative electrode, and a battery case in which the positive electrode, the negative electrode, and the electrolyte are accommodated,
The negative electrode has a metal negative electrode member and an n-type semiconductor portion electrically connected to the negative electrode member via a metal layer. The battery case includes an n-type semiconductor portion of the negative electrode. Is provided with a light-receiving portion that allows light to enter, so that the light energy can be adjusted by utilizing the bending of the energy band formed by contacting the n-type semiconductor portion in the electrolyte.
It is charged by converting it to electrochemical energy, and at the time of discharging, it is discharged by oxidizing the metal negative electrode member with oxygen.

At the time of charging, light energy is applied to the n-type semiconductor portion to excite electrons in the conduction band of the n-type semiconductor portion to generate holes in the valence band. Carry this hole to the electrolyte side along the bending of the energy band,
It reacts with hydroxyl ions on the surface of the negative electrode member to generate oxygen and water. On the other hand, the electrons excited in the conduction band move to the negative electrode member along the bending of the energy band, and react with water in the electrolyte on the surface of the negative electrode member to reduce the negative electrode member oxidized by the discharge. Therefore, the light-air secondary battery of the present invention can be charged in any of the energy forms of electricity and light.

Also, since an oxygen catalyst is used for the positive electrode,
Discharge using oxygen in the air as an energy source (active material) is possible. Accordingly, a sufficient amount of the positive electrode active material can be easily replenished from the air, and a light-air secondary battery having a high energy density and excellent in economy and energy saving can be realized. In particular, the negative electrode has a metal layer electrically connected to a metal negative electrode member to reduce a barrier in an energy band at a metal-semiconductor interface, and the metal layer includes a negative electrode member and an n-type semiconductor portion. Thus, electric energy can be generated in the n-type semiconductor portion by light energy, and the electric energy can be transmitted to the negative electrode member through the metal layer. For this reason, the transmission efficiency of the electric energy transmitted from the n-type semiconductor portion to the negative electrode member can be increased. Then, since the n-type semiconductor portion and the negative electrode member are integrally bonded via the metal layer, the negative electrode and the photoelectrode in the conventional photochemical secondary battery can be integrated, and a simple two-electrode of the positive electrode and the negative electrode can be obtained. The configuration enables light charging, and further eliminates the need for devices such as a voltage adjustment circuit and a backflow prevention diode, and eliminates the need for advanced manufacturing techniques such as pn junction technology. Manufacturing workability can be improved.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first embodiment of a light-air secondary battery according to the present invention.

FIG. 2 is a perspective view of FIG.

FIG. 3 is a block diagram showing a change in voltage between a positive electrode terminal and a negative electrode terminal during charging and discharging of the light-air secondary batteries of the first embodiment and the comparative example of the light-air secondary battery of the present invention. is there.

FIG. 4 is a sectional view showing a second embodiment of the photo-air secondary battery of the present invention.

FIG. 5 shows an equivalent circuit of a conventional photo-air secondary battery.

FIG. 6 is a front view showing a configuration diagram of a conventional photochemical secondary battery.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Positive electrode 11 Negative electrode 11a Negative electrode member 11b Metal layer 11c N-type semiconductor part 12 Electrolyte 13 Separator 16 Battery case 16a Light receiving part 16b Air transmitting part 16b 'Bottom part

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Tsutomu Ogata 1-6, Uchisaiwaicho, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Corporation (56) References JP-A-6-325801 (JP, A) JP-A Heisei JP-A-6-223889 (JP, A) JP-A-6-223888 (JP, A) JP-A-6-215807 (JP, A) JP-A-6-215806 (JP, A) JP-A-5-266932 (JP, A A) JP-A-5-198319 (JP, A) JP-A-52-74831 (JP, A) Keiji Akudo, Naoki Kato, Masaaki Takeuchi, Tsutomu Ogata, Optical Air Secondary Battery, IEICE Technical Research Report, Japan, The Institute of Electronics, Information and Communication Engineers, January 24, 1992, Vol. 91 / No. 439, p. 15-20 Naoki Kato, Keiji Akudo, Masaaki Takeuchi, Tsutomu Ogata, Charge and Discharge Behavior of GaP-Co / O2-based Light-Air Secondary Battery, Proceedings of the 59th Annual Meeting of the Electrochemical Association, Japan, Japan Electric Corporation Chemical Society, March 19, 1992, p. 222 Keiji Akudo, Naoki Kato, Masaaki Takeuchi, Tsutomu Ogata, Charging / discharging behavior of Ti / O2-based photo-air secondary battery-Charging by photo-reaction of discharge product itself-, Proc. Of the 59th Annual Meeting of the Electrochemical Society, Japan, The Electrochemical Society, March 19, 1992, p. 222 (58) Field surveyed (Int.Cl. ⁷ , DB name) H01M 14/00 H01L 31/04 JICST file (JOIS)

Claims (2)

(57) [Claims] Claims: 1. A positive electrode having an oxygen catalyst, a negative electrode, an electrolyte in contact with the positive electrode and the negative electrode, and a battery case containing the positive electrode, the negative electrode, and the electrolyte, wherein the negative electrode includes: A metal negative electrode member, a metal layer electrically connected to the negative electrode member, which reduces a barrier in an energy band at a metal-semiconductor interface, and an n-type semiconductor portion electrically connected to the metal layer. The metal layer is integrally adhered between the negative electrode member and the n-type semiconductor portion, and the battery case is provided with a light receiving portion for entering light into the n-type semiconductor portion of the negative electrode. A light-air secondary battery characterized by the above-mentioned. 2. The negative electrode member is discharged by an oxidation reaction and an oxygen reduction reaction of the negative electrode member, and by applying light energy to the n-type semiconductor portion, the negative electrode member oxidized by the discharge is reduced and charged. The light-air secondary battery according to claim 1, wherein: